Most people arrested as the result of FBI terrorism investigations are charged with non-terrorism offenses, and more domestic terror suspects were arrested last year than those allegedly inspired by international terror groups, according to internal FBI figures reviewed by The Washington Post.

As government officials and activists debate the best way to pursue violent extremists, the figures show how much of counterterrorism work goes undeclared and unnoticed. Thousands are investigated each year. Hundreds are charged with crimes. But the public and the media see only dozens.

The debate centers on whether federal law and law enforcement are too focused on Islamic terrorism and not paying enough attention to the rise in far right-wing extremism. In fact, according to the data, more domestic terrorist targets are being charged, and in both categories, law enforcement officials often leverage simpler crimes, such as violations of gun or drug laws, to prevent violence.

“It’s violence that we key in on,” said a senior law enforcement official who spoke on the condition of anonymity to discuss sensitive federal investigative work. “And sometimes, it’s the violence that motivates someone more than any particular ideology.”

The arrest last month of Coast Guard Lt. Christopher P. Hasson, 49, is the latest example of this pattern. Prosecutors have alleged Hasson is a white nationalist inspired in part by mass murderer Anders Behring Breivik, who in 2011 unleashed two attacks in Norway that killed 77 people.

Hasson, who has been detained since his arrest, is accused of amassing weapons as part of a domestic terror plot targeting politicians and journalists. Authorities have highlighted a letter in which he allegedly wrote, “I am dreaming of a way to kill almost every last person on the earth.”

But as with most people arrested in FBI counterterrorism investigations, Hasson does not yet face terrorism charges. Rather, he was indicted on charges of illegal possession of firearm silencers, possession of firearms by a drug addict and unlawful user, and possession of a controlled substance.

According to FBI figures shared with The Post, in the 2017 budget year there were about 110 people arrested after being investigated for actions inspired by foreign terror groups such as the Islamic State and al-Qaeda. Of those, about 30 faced terrorism charges. The rest faced gun, drug, fraud or immigration charges.

Last year, out of about 100 such arrests, only nine defendants faced terrorism charges — a drop-off owed in part to a decline in the number of people attempting to travel overseas to join the Islamic State, the senior law enforcement official said.

This image provided by the U.S. District Court in Maryland shows firearms and ammunition allegedly amassed by Coast Guard Lt. Christopher P. Hasson. (AP)

In the 2017 budget year, FBI investigations led to the arrest of about 150 domestic terrorism suspects, according to law enforcement officials. The following year, the figure was about 120.

But because federal law does not designate domestic groups as terrorist organizations, no corresponding terrorism crimes apply to such suspects. And while the number of such arrests fell last year, the senior law enforcement official emphasized that, overall, more domestic terrorism suspects are being arrested.

About one in four counterterrorism arrests are made by state and local authorities — not the FBI, the senior law enforcement official said.

Seamus Hughes, deputy director of the Program on Extremism at George Washington University, said the figures explain how counterterrorism work is done.

“You’re going to arrest someone with whatever charges you have to negate the threat. The FBI doesn’t need to pad stats on terrorism if it means getting a terrorist off the streets,” Hughes said.

He warned, though, that charging practices may be unintentionally misleading to the public, presenting an incomplete picture of law enforcement’s work to keep Americans safe. Hughes tracks terrorism cases independently as part of his work and said that he identified about 65 such cases last year, far less than the total figure of more than 200 people charged after an FBI investigation.

“If I missed it, I’m sure many others did, too,” Hughes said. “. . . Unless the public understands that terrorism cases don’t necessarily mean terrorism charges or convictions, you don’t get a sense of the scope of the threat, whether it’s domestic terrorism or international.”

With Hasson, the absence of terrorism charges could have a significant effect on how his case is handled. At a court hearing last month in Maryland, the judge, Charles B. Day, said it would be unusual to detain someone without bail based on the gun and drug charges Hasson faces now. He has not yet entered a plea.

Prosecutors have labeled Hasson a “domestic terrorist” who planned to murder innocent civilians. His lawyer, Julie Stelzig, said the government’s description is “histrionic” and that there was “no actual indication of any plan. . . . It’s not a crime to think negative thoughts. It’s not a crime to think about doomsday scenarios.”

A case in Tucson similarly highlights the complicated factors prosecutors must weigh before filing terrorism charges.

In April 2017, Ahmad Suhad Ahmad was the focus of an intense FBI undercover operation. Ahmad, who allegedly bragged to a government informant about the bombmaking skills he developed in his native Iraq, was brought to a Las Vegas condominium by an undercover FBI agent posing as a member of a Mexican drug cartel who wanted to kill an enemy, according to court records.

Prosecutors say that once in the condo, Ahmad assembled a bomb using materials he brought and others supplied by the undercover agent. Authorities charge that Ahmad also showed the undercover agent how to build a bomb, but those devices did not contain real explosives.

Two months later, Ahmad, 30, was arrested, jailed and charged with violating his parole for an unrelated drug charge. He was released in September and rearrested a month later on two federal drug charges and two counts of distributing information related to explosives.

The second arrest came after a lengthy internal debate among Justice Department and FBI officials over whether the evidence supported terrorism charges, according to people familiar with the matter who spoke on the condition of anonymity to discuss internal deliberations.

At a court hearing late last year, U.S. Magistrate Judge Eric J. Markovich noted an apparent contradiction in the government’s case — that the suspect prosecutors argued was too dangerous to release on bail had been free for months after the FBI’s undercover sting. Assistant U.S. Attorney Kevin Hakala insisted that Ahmad “was being very closely monitored” after the alleged bomb-building trip to Las Vegas.

Ahmad has pleaded not guilty and was ordered held without bail until his trial, which is scheduled for May. His lawyer, Walter Goncalves Jr., told the judge that the FBI’s handling of the case showed Ahmad was not dangerous, saying his client had a drug problem leading to his 2017 arrest.

“He was, unfortunately, using drugs and was addicted and was not thinking clearly,” Goncalves Jr. said.

“It’s kind of odd,” the judge remarked, “you’ve let him out on the streets.”